Characterization and application of a sterol esterase immobilized on polyacrylate epoxy-activated carriers (DilbeadsTM)

The sterol esterase from the ascomycete Ophiostoma piceae was immobilized on novel polyacrylate-based epoxy-activated carriers (DilbeadsTM). Six supports with particle sizes between 120-165 micrometers were prepared varying the composition of monomers, crosslinkers and porogens. Their surface areas and porosities were determined by N2 adsorption and mercury intrusion porosimetry. The pore volumes ranged from 0.63 to 1.32 cm3/g, but only DilbeadsTM RS and NK had narrow pore size distributions (with maxima at 33.5 and 67.0 nm, respectively). The distribution of the enzyme in the support was studied by fluorescence confocal microscopy. The immobilized esterase on DilbeadsTM TA showed a significant pH and thermal stability and was assayed in the continuous hydrolysis of cholesteryl esters -present in the pulp industry process waters-.We thank Mª Teresa Seisdedos (Centro de Investigaciones Biologicas, CSIC) for help with the confocal microscopy. This research was supported by the Spanish Ministry of Education and Science (Projects BIO2002-00337 and BIO2003-00621) and Comunidad de Madrid (Project S-0505/AMB0100). We thank CSIC for a research fellowshipPeer reviewe

Construction of logic gates exploiting resonance phenomena in nonlinear systems.

A two-state system driven by two inputs has been found to consistently produce a response mirroring a logic function of the two inputs, in an optimal window of moderate noise. This phenomenon is called logical stochastic resonance (LSR). We extend the conventional LSR paradigm to implement higher-level logic architecture or typical digital electronic structures via carefully crafted coupling schemes. Further, we examine the intriguing possibility of obtaining reliable logic outputs from a noise-free bistable system, subject only to periodic forcing, and show that this system also yields a phenomenon analogous to LSR, termed Logical Vibrational Resonance (LVR), in an appropriate window of frequency and amplitude of the periodic forcing. Lastly, this approach is extended to realize morphable logic gates through the Logical Coherence Resonance (LCR) in excitable systems under the influence of noise. The results are verified with suitable circuit experiments, demonstrating the robustness of the LSR, LVR and LCR phenomena. This article is part of the theme issue \u27Vibrational and stochastic resonance in driven nonlinear systems (part 1)\u27

Electrochemical behavior of Serratia marcescens ACE2 on carbon steel API 5L-X60 in organic/aqueous phase

10.1021/ie8005935Industrial and Engineering Chemistry Research47186925-6932IECR